This invention relates to a special receptacle or package, and more particularly to a reclosable sterile collection bag having a wire closure mechanism.
Bags having wire closure mechanisms are currently used to obtain industrial, chemical, and forensic material samples in a sterile manner. For example, U.S. Pat. No. 2,973,131 describes a collection bag having metal wires. Strips of pressure sensitive tape are used to attach the metal wires to opposite sides of the bag. Both the wires and the tape project beyond the side edges of the bag. During use, the bag is filled, the mouth of the bag is closed and rolled against the body of the bag, and the projecting portions of the metal wires are folded back to clamp the rolled end closed. This arrangement has a number of disadvantages. Particularly, the bag can be difficult to open, the wire may not be centered under the tape, and the projecting metal wire ends may puncture adjacent bags during transport prior to use or may puncture a closed bag.
Later inventions have been made to improve the ease with which the bag may be opened. For example, U.S. Pat. Nos. 3,189,253; 4,356,954; and 5,180,220 each use center pull tabs. U.S. Pat. No. 4,356,954 uses downwardly-directed strip ends. U.S. Pat. No. 5,180,229 encloses the wire ends with an additional length of covering material. Although helpful, the arrangements of the above patents are difficult and costly to manufacture and do not result in complete effectiveness with regard to eliminating bag punctures. Further, several targeted improvements have resulted in problems of their own, such as pull tabs or tear strips becoming separated from their bags and falling into (and therefore contaminating) foodstuffs or other products. Thus, a need yet exists for a sterile collection bag that avoids the problems of the prior art sterile collection bags. Ideally, such a bag would be easy to manufacture and convenient to use. In addition, the components of such a bag would not cause premature punctures to the bag body before use or during transport.
The present invention provides a novel sterile collection bag. The bag includes a body and an opening mechanism. The body is formed of opposed sidewalls and includes an upper body end adjacent to the mouth opening. The interior of the body defines a sterile collection space for a sample object or fluid. The opening mechanism includes first and second flexible closure strips, each having a first end, a second end, and a midsection. In the preferred embodiment, the strips are constructed of plastic with an integrated, centrally located metal wire. The strips are attached to the sidewalls of the bag body and are longer than the width of the body so as to project beyond the sidewall edges. In the preferred embodiment, the projecting ends of the strips are secured to one another. In an alternative embodiment, the projecting ends of the strips are not secured to one another.
In accordance with other aspects of the invention, the ends of each plastic strip can be formed with central indentations adjacent to the ends of the embedded wires. This causes the wire ends to be recessed from the strip ends in such a manner as to reduce the likelihood of unintended bag punctures.
In accordance with another aspect of the invention, the bag is designed in such a way as to prevent the intrusion of air and other contaminants to the interior sterile collection space until its initial use, by sealing the top of the bag. In one embodiment, the bag is formed of linearly oriented polymer film, and one or more lateral notches are cut slightly above the location of the attached flexible closure strips. In another embodiment, non-oriented polymer is used, and the small lateral notches are positioned to facilitate lateral tearing between the two notches, guided by an adjacent edge of a closure strip. These embodiments allow the top of the bag to be torn away for opening upon initial use, but prevent air and other contaminants from entering the interior sterile collection space beforehand.
In accordance with a further aspect of the invention, the opening mechanism includes first and second pull tabs. Each pulltab is attached to the midsection of one of the bag sidewalls, and is constructed of a thin polymer film. In accordance with one aspect of the invention, these pull tabs may be colored in such a manner as to facilitate visual distinction of the pull tabs within the sample collection environment. Similarly, the upper portion of a bag to be torn away for opening can be brightly colored or otherwise prominently marked so that it will be readily visible after removal.